Simple ruby script to take a json file and output it in a nicely indented format

prettify_json.rb

#! /usr/bin/env ruby

require 'json'

unless ARGV.length == 1
  puts "
Usage: prettify_json.rb path/to/file.json

It's simple! It is strongly recommended that you redirect any errors to an
error.txt file (to make them easy to read) as follows...

  eg. prettify_json.rb path/to/input.json 2> error.txt

You can also redirect the prettified json output to a file too...

  eg. prettify_json.rb path/to/input.json 2> error.txt > output.json 
"
  exit 1
end

input_filepath = ARGV.first

unless File.exist?(input_filepath)
  puts "File '#{input_filepath}' not found."
  exit 1
end
pretty_json = ''
text = File.read(input_filepath)

begin
  json = JSON.parse(text)
  pretty_json = JSON.pretty_generate(json)
rescue
  $stderr.puts "#{$!}\n#{$!.backtrace.join("\n")}"
end
puts pretty_json